I just put together a new desktop. Bought the case, power supply, motherboard, processor, etc and connected everything up. I purchased Windows 7 Pro OEM, and now I find "If the individual software license is for a desktop operating system or application software, it also must be preinstalled on the hard drive of the fully assembled computer system, using the OEM Preinstallation Kit (OPK)." I'm not sure I understand this. Do I need another computer to accomplish this? If I had an external drive enclosure, do I somehow (OPK process running on a laptop?) install the OS to that drive, then take the disk out and re-install it in the desktop case? If anyone has had experience on setting up a completely virgin PC, I'd appreciate tips. Thanks.